Work has begun on the longest oil pipeline in Russia, two days after President Putin changed the proposed route to avoid approaching Lake Baikal.

When completed, it will carry oil from eastern Siberia to the Pacific Ocean for consumers across the Asia-Pacific region, including China.

The completed pipeline will run for more than four thousand kilometres and will be finished in 2008.

It will be the longest pipeline in the world's largest country.

Work has started near the town of Taishet in Siberia.

The pipeline is being built to supply the ever-growing demand for oil in China and the rest of the Asia-Pacific region.

EAST SIBERIAN PIPELINE

Length: 4,130km

Capacity: 80m tons annually

First stage (to Skovorodino near China border) to be finished in 2008

Second stage (to Perevoznaya on Pacific coast) - by 2015

Project cost: $11.5bn (£6.4bn)

Forecasts quoted by the company building the pipeline, Transneft, suggest that consumption of oil there will grow by more than 50% between 2002 and 2010, and more than double between 2002 and 2020.

Work is getting underway just two days after President Vladimir Putin ordered that the route of the pipeline be changed.

Originally, it would have passed within 800 metres of the shores of Lake Baikal, the world's largest body of fresh water.

Environmental groups had expressed the fear that an oil spill could have caused irreversible damage to the lake, which is home to hundreds of unique species, and there had been mass demonstrations in Irkutsk, the regional capital.

The financial cost of the change of the change of route has yet to be determined.

Earlier in the week, Transneft vice-president Sergey Grigoryev told BBCRussian.com. that "any extension of the route makes it unprofitable."

Russia is already a large supplier of energy, including gas, to Europe.

President Putin has recently made it clear that he wants to diversify the energy markets it supplies, and is particularly looking to Asia.

Russia will be hosting the G8 Summit in St Petersburg in July, with a theme of energy security.